The present invention is related to a vehicles heating system.
Passenger comfort and fuel efficiency have set forth increasing demands on automotive heating, ventilating and air-conditioning (HVAC) systems. It is a primary goal of most HVAC systems to provide a more efficient means for providing climate control to an automobile.
As a result, newer and improved automotive HVAC systems are configured to make use of available energy sources without placing an additional load onto the vehicle system.
Presently, automotive vehicles are supplied with heating systems that utilize heat produced by the vehicle""s engine. The system includes a heater core configured to disapate heat into the vehicles HVAC system. Water or engine coolant that is heated by the engine is transported through a conduit from the engine block to the heater core.
A user controlled variable speed fan is positioned upstream from the heater core. The HVAC system typically includes a path which extends directly through the heater core as well as a parallel path which bypasses the heater core with an adjustably positioned vent door to control the amount of air directed through the heater core.
In vehicles having relatively large engines, such as 6 or 8 cylinder engines, the engine size is considered large enough to provide a sufficient amount of heat to the passenger compartment. However, the engine must be first warmed up to provide a source of heat.
However, the time required to heat an engine up to its operational temperature may take several minutes. Moreover, the actual time required may vary in accordance with the size and type of engine as well as the outside temperature.
Vehicles that have smaller or more fuel efficient engines, are sometimes unable to produce enough heat even when they have reached their operational temperature. This is particularly true on extremely cold days when the ambient temperature is well below freezing. Accordingly, and as automobiles become more fuel efficient, they generate less heat.
In addition, and during regular operation, if an engine is set into an idling mode, the engine runs at a lower rpm. This may also cause engine to generate less heat which ultimately causes less heat to be transferred to the interior of the automobile.
Diesel engines are particularly susceptible to this problem as there is a much greater difference between the heat produced at an idle versus the heat generated during regular operation.
Additionally, and when an engine is shut off after it has been running at its operational temperature, the engine""s heat is no longer transferred to the vehicle""s heating system since the water pump which is driven by the engine through mechanical linkage is unavailable to be operated.
It is therefore an object of the invention to provide an improvement in the performance of a heating system of an automotive vehicle.
Another object is to provide a method and apparatus for supplementing and/or improving the heating system of an automotive vehicle.
Another object of the present invention is to provide a method and apparatus for improving the heating system of an automobile without affecting the energy load and accordingly the fuel efficiency of the automobile engine.
Another object of the present invention is to provide a method and apparatus for improving the heating system of an automobile without affecting the cabin air temperature control quality. (The dynamic changes of hybrid vehicle propulsion modes result in unpredictable switching from one heating loop to the others. Cabin supply air temperature tends to be unstable and less controllable as a result of alternating the heat sources).